Medicine

Besides the obvious benefits of using snake venom to produce antivenin there been other breakthroughs in medical research. There have been early results from research that gives promise on many medical fronts. In France, an enzyme derived from copperhead venom may hold an answer to treatment for breast cancer. Enzymes from cobra venom may hold the key to finding cures for Parkinson's disease and Alzheimer's disease. Some viper venom seems to hold the secrets to curing osteoporosis and promoting tumour reduction. Several venom extracts have shown lead to anticoagulants that would be helpful in treating heart disease and strokes. Proteins from certain rattlesnakes have produced blood pressure medicine. Ingredients from the red-necked spitting cobra have provided clues to breaking down cell membranes that could provide treatment for leukaemia and cancer. It is obvious that the very complex enzymes derived from snake venom could produce potentially huge medical benefits for mankind. Two anticoagulants, one which has FDA approval, have been developed -Ancord and Aggrastat®.

Ancord

Ingredients from the venom of a Malayan pit viper have shown promise in breaking down blood clots that would be very beneficial in treating stroke victims. The drug made from snake venom, called ANCROD, was given intravenously over a three-to-five day period after a stroke occurred. Researchers turned to the pit viper snake after discovering blood did not clot in people bitten by this snake. Ancrod lowers levels of fibrinogen, a natural substance that helps blood clot. The study found 42 percent of stroke patients who received Ancord within three hours after the onset of the stroke had recovered the physical and mental abilities they had before the stroke, compared with 34 percent of stroke patients who received a placebo. However, 5 percent of the Ancord group suffered bleeding in the brain, compared with 2 percent of the placebo group. The drug has yet to be approved by the FDA.

Image taken from http://homepages.webleicester.co.uk/fester/photo.htm

Aggrastat®

Merck Research labs analysed the venoms of several viper species and noticed a new family of proteins responsible for the anticoagulant action of the venoms. These proteins, called disintegrins, naturally prevent platelets from sticking together. The venom of the African saw-scaled viper was used because the chemical sequence was simple and therefore easily synthesised in the lab. The Merck research team and Temple University isolated and synthesised echistatin, the small protein from the venom of the saw scaled viper that interferes with blood clotting. When synthesising the echistatin they studied the specific regions of the protein that stopped platelets from sticking together and developed a drug that would not be toxic to patients. After taking ten years they produced a marketable drug, Aggrastat® (tirofiban HCL), that blocks certain blood platelet receptors. The drug does not actually contain the snake venom, only a synthesised organic molecule that mimics the anti-clotting behaviour of saw-scaled viper venom. Designed for prescription to heart attack patients, Aggrastat® obtained FDA approval May 14, 1998.

Image taken from http://www.kingsnake.com/saw_scale